Abstract: Functionalized fibers adapted to remove contaminants from water and soil are produced in accordance with a single-step process that involves treating an acrylic fiber with an amination reagent to form a functionalized acrylic amino fiber. By way of another single-step process, functionalized acrylic amino fibers are treated with an alkylating reagent to form functionalized acrylic quaternary amino fibers.

Abstract: The present disclosure provides for a method for producing porous granular composite iron having high permeability, hydrophilicity, reactivity, and capacity for treatment of inorganic and organic contaminants. The method may include the steps of: mixing iron powder, or iron/metal mixture and adsorbent powders, with surface modifier and binder compounds to form a granular material. This granular material is used in a filter, vessel, and in situ permeable reactive barrier by passing a contaminated liquid stream through a bed of the granular product for removal of the contaminants. The porous granular iron materials have low bulk density, do not fuse together and can be regenerated for reuse.

Abstract: The present disclosure provides for a method for producing porous granular composite iron having high permeability, hydrophilicity, reactivity, and capacity for treatment of inorganic and organic contaminants. The method may include the steps of: mixing iron powder, or iron/metal mixture and adsorbent powders, with surface modifier and binder compounds to form a granular material. This granular material is used in a filter, vessel, and in situ permeable reactive barrier by passing a contaminated liquid stream through a bed of the granular product for removal of the contaminants. The porous granular iron materials have low bulk density, do not fuse together and can be regenerated for reuse.

Abstract: A graphene oxide adsorbent for removing dissolved substances from water or other liquids comprises a substrate having a coating layer of graphene oxide. The dissolved substances may be dissolved heavy metals, radioactive compounds, or other organic and inorganic substances. The substrates may be particulate substrates. The substrates may be adsorbents. The graphene oxide adsorbents can be beneficially used in filters and batch reactors, among other devices, for water treatment and for environmental remediation.

Abstract: A method for removing dissolved contaminants from solution using a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants, in particular, arsenate and arsenite. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated titanium oxide is combined with other filter media to further improve the removal of dissolved contaminants.

Abstract: A method for removing dissolved contaminants from solution using a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants, in particular, arsenate and arsenite. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated titanium oxide is combined with other filter media to further improve the removal of dissolved contaminants.

Abstract: A process for stabilizing chromium in a chromite ore processing residue (COPR) comprises the steps of adding an acid to consume the excess alkalinity of the COPR, resulting in a pH of less than 10; and adding a chemical reductant to the COPR to convert any hexavalent chromium present to trivalent chromium. A source of sulfate may be added to the COPR to reduce heave potential and improve its geotechnical stability. Treated COPR may be encapsulated in a material suitable to prevent contact between the COPR and water, such as an asphalt.

Abstract: A process for stabilizing chromium in a chromite ore processing residue (COPR) comprises the steps of adding an acid to consume the excess alkalinity of the COPR, resulting in a pH of less than 10; and adding a chemical reductant to the COPR to convert any hexavalent chromium present to trivalent chromium. A source of sulfate may be added to the COPR to reduce heave potential and improve its geotechnical stability. Treated COPR may be encapsulated in a material suitable to prevent contact between the COPR and water, such as an asphalt.

Abstract: A method for removing dissolved contaminants from solution using a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants, in particular, arsenate and arsenite. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated titanium oxide is combined with other filter media to further improve the removal of dissolved contaminants.

Abstract: A method for removing dissolved contaminants from solution using a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants, in particular, arsenate and arsenite. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated titanium oxide is combined with other filter media to further improve the removal of dissolved contaminants.

Abstract: A water filtration device (3) and method which removes heavy metals and organic compounds from raw water is provided.

Abstract: A method for producing a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants includes the steps of preparing a titanium oxide precipitate from a mixture comprising a hydrolysable titanium compound and heating the precipitate at a temperature of less than 300° C., without calcining the precipitate. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated crystalline titanium oxide product is used in methods to remove dissolved inorganic contaminants from dilute aqueous streams by suspending the product in an aqueous stream or by filtering an aqueous stream through a bed of the product. In another method, a hydrolysable titanium compound is added to an aqueous stream so that titanium oxides form as a co-precipitate with dissolved contaminants within a bed of particulate material.

Abstract: Dissolved inorganic contaminants are removed from a dilute aqueous stream by adding a hydrolysable metal compound to the aqueous stream, co-precipitating a hydrolyzed metal compound with the inorganic contaminants, and, concurrently with the co-precipitation step, filtering the co-precipitate from the dilute aqueous stream using a packed bed filter. The process may be carried out so that the metal oxide co-precipitate forms within the packed bed. Dissolved contaminants, particularly arsenic compounds, are removed more efficiently than by conventional co-precipitation/filtration processes. An apparatus for carrying out the process provides for injection of the hydrolysable metal compound into the dilute aqueous stream immediately upstream of the packed bed filter, without an intervening flocculation or sedimentation vessel, thereby providing an effective contaminant removal system that requires a smaller footprint and lower capital cost than conventional water treatment systems.

Abstract: A method for producing a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants includes the steps of preparing a titanium oxide precipitate from a mixture comprising a hydrolysable titanium compound and heating the precipitate at a temperature of less than 300° C., without calcining the precipitate. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated crystalline titanium oxide product is used in methods to remove dissolved inorganic contaminants from dilute aqueous streams by suspending the product in an aqueous stream or by filtering an aqueous stream through a bed of the product. In another method, a hydrolysable titanium compound is added to an aqueous stream so that titanium oxides form as a co-precipitate with dissolved contaminants within a bed of particulate material.